What is HMRC’s online filing service?
Since 2011, HMRC has offered a free online service that allows small companies to file their annual accounts and Corporation Tax return (CT600) together in one step. This joint filing system also forwards accounts to Companies House, simplifying compliance for small, unrepresented businesses.
The service was widely used by small companies with straightforward financial affairs, including dormant companies and some incorporated charities, as it eliminated the need for commercial filing software.
Why is the service closing?
HMRC and Companies House have announced the joint service will close permanently on 31 March 2026.
The system is outdated and no longer meets current digital standards or evolving legislative requirements. HMRC is encouraging businesses to switch to modern commercial software that offers improved functionality, such as automated checks and compatibility with updated filing obligations. Companies House is also moving toward a fully digital future, supported by reforms introduced under the Economic Crime and Corporate Transparency Act.
Who will be affected?
This change primarily impacts small companies and unrepresented businesses currently using the joint filing service. Most companies already use dedicated software or an accountant, so will see minimal disruption.
Accountants may also need to assist clients who have been self-filing through HMRC’s portal, ensuring they transition smoothly to compliant software ahead of the deadline. Although, this is unlikely to impact many businesses as an accountant would normally already be using appropriate software to file their clients accounts and Corporation Tax Return.
What should businesses do before the service closes?
To avoid disruption, affected businesses should begin preparing now:
- Choose a new filing method: Select an HMRC-approved commercial software package that can submit CT600 returns and iXBRL accounts. Alternatively, engage a professional accountant to manage your filings.
- Back up your records: Download and securely store copies of your past returns filed through HMRC’s portal. After 31 March 2026, you won’t be able to access them. HMRC recommends downloading the last three years of filings.
- Transition early: Get familiar with the new software or processes well before the deadline. This helps avoid issues when the HMRC service is withdrawn.
- Check eligibility for paper filing (if applicable): In rare cases, such as dormant companies or charities, paper filing may still be permitted – but this requires HMRC approval and is not the default.
How will companies file returns after the closure?
From 1 April 2026, businesses will need to file their accounts and tax returns separately with HMRC and Companies House:
- For Corporation Tax: Returns must be submitted using commercial software that supports CT600 forms, tax computations, and iXBRL accounts. The HMRC portal will no longer be available.
- For Companies House: Businesses can continue using WebFiling or suitable third-party software to submit their accounts. While paper filing is still allowed in limited cases, Companies House plans to mandate software-only filing in the future.
Many businesses will find it efficient to adopt integrated software that handles both filings. These tools often include compliance checks and digital record-keeping features that can streamline the process.
Final thoughts
Although the closure of the filing service may seem to be a hassle for many, the move reflects HRMC’s shift towards securing and modernising digital compliance. Companies that act early will reduce the risk of non-compliance and benefit from improved tools for managing their financial reporting.
If you’re unsure how to prepare for these changes, Ward Goodman is here to help. Our expert team can support you in selecting the right software, handling the transition, or managing your filings directly. Get in touch today to ensure your business remains compliant and well-prepared.
